X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FSjLjEHPrepare.cpp;h=059e8d6c19aa51663be9e069a5294ae107f0a3c8;hb=35a389344d21178ee280c2410401b2060b5b879c;hp=e987fa2fbc8e46570af464ccc689d21eba1f32bf;hpb=b01bbdcc1af27bd90b552bb1b62b48916e0d4be3;p=oota-llvm.git diff --git a/lib/CodeGen/SjLjEHPrepare.cpp b/lib/CodeGen/SjLjEHPrepare.cpp index e987fa2fbc8..059e8d6c19a 100644 --- a/lib/CodeGen/SjLjEHPrepare.cpp +++ b/lib/CodeGen/SjLjEHPrepare.cpp @@ -27,7 +27,6 @@ #include "llvm/ADT/Statistic.h" #include "llvm/ADT/SmallVector.h" #include "llvm/Support/CommandLine.h" -#include "llvm/Support/Compiler.h" #include "llvm/Support/Debug.h" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetLowering.h" @@ -38,20 +37,20 @@ STATISTIC(NumUnwinds, "Number of unwinds replaced"); STATISTIC(NumSpilled, "Number of registers live across unwind edges"); namespace { - class VISIBILITY_HIDDEN SjLjEHPass : public FunctionPass { + class SjLjEHPass : public FunctionPass { const TargetLowering *TLI; const Type *FunctionContextTy; Constant *RegisterFn; Constant *UnregisterFn; - Constant *ResumeFn; Constant *BuiltinSetjmpFn; Constant *FrameAddrFn; Constant *LSDAAddrFn; Value *PersonalityFn; Constant *SelectorFn; Constant *ExceptionFn; + Constant *CallSiteFn; Value *CallSite; public: @@ -67,8 +66,8 @@ namespace { } private: - void markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, - Value *CallSite, + void insertCallSiteStore(Instruction *I, int Number, Value *CallSite); + void markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite, SwitchInst *CatchSwitch); void splitLiveRangesLiveAcrossInvokes(SmallVector &Invokes); bool insertSjLjEHSupport(Function &F); @@ -107,27 +106,33 @@ bool SjLjEHPass::doInitialization(Module &M) { Type::getVoidTy(M.getContext()), PointerType::getUnqual(FunctionContextTy), (Type *)0); - ResumeFn = - M.getOrInsertFunction("_Unwind_SjLj_Resume", - Type::getVoidTy(M.getContext()), - VoidPtrTy, - (Type *)0); FrameAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::frameaddress); BuiltinSetjmpFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_setjmp); LSDAAddrFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_lsda); SelectorFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_selector); ExceptionFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_exception); + CallSiteFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_callsite); PersonalityFn = 0; return true; } +/// insertCallSiteStore - Insert a store of the call-site value to the +/// function context +void SjLjEHPass::insertCallSiteStore(Instruction *I, int Number, + Value *CallSite) { + ConstantInt *CallSiteNoC = ConstantInt::get(Type::getInt32Ty(I->getContext()), + Number); + // Insert a store of the call-site number + new StoreInst(CallSiteNoC, CallSite, true, I); // volatile +} + /// markInvokeCallSite - Insert code to mark the call_site for this invoke -void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, +void SjLjEHPass::markInvokeCallSite(InvokeInst *II, int InvokeNo, Value *CallSite, SwitchInst *CatchSwitch) { ConstantInt *CallSiteNoC= ConstantInt::get(Type::getInt32Ty(II->getContext()), - InvokeNo); + InvokeNo); // The runtime comes back to the dispatcher with the call_site - 1 in // the context. Odd, but there it is. ConstantInt *SwitchValC = ConstantInt::get(Type::getInt32Ty(II->getContext()), @@ -144,15 +149,17 @@ void SjLjEHPass::markInvokeCallSite(InvokeInst *II, unsigned InvokeNo, } } - // Insert a store of the invoke num before the invoke and store zero into the - // location afterward. - new StoreInst(CallSiteNoC, CallSite, true, II); // volatile + // Insert the store of the call site value + insertCallSiteStore(II, InvokeNo, CallSite); + + // Record the call site value for the back end so it stays associated with + // the invoke. + CallInst::Create(CallSiteFn, CallSiteNoC, "", II); // Add a switch case to our unwind block. CatchSwitch->addCase(SwitchValC, II->getUnwindDest()); - // We still want this to look like an invoke so we emit the LSDA properly - // FIXME: ??? Or will this cause strangeness with mis-matched IDs like - // when it was in the front end? + // We still want this to look like an invoke so we emit the LSDA properly, + // so we don't transform the invoke into a call here. } /// MarkBlocksLiveIn - Insert BB and all of its predescessors into LiveBBs until @@ -272,8 +279,8 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { SmallVector Invokes; // Look through the terminators of the basic blocks to find invokes, returns - // and unwinds - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) + // and unwinds. + for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) { if (ReturnInst *RI = dyn_cast(BB->getTerminator())) { // Remember all return instructions in case we insert an invoke into this // function. @@ -283,6 +290,7 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { } else if (UnwindInst *UI = dyn_cast(BB->getTerminator())) { Unwinds.push_back(UI); } + } // If we don't have any invokes or unwinds, there's nothing to do. if (Unwinds.empty() && Invokes.empty()) return false; @@ -382,9 +390,6 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { I->eraseFromParent(); } - - - // The entry block changes to have the eh.sjlj.setjmp, with a conditional // branch to a dispatch block for non-zero returns. If we return normally, // we're not handling an exception and just register the function context @@ -398,13 +403,15 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { // Insert a load in the Catch block, and a switch on its value. By default, // we go to a block that just does an unwind (which is the correct action // for a standard call). - BasicBlock *UnwindBlock = BasicBlock::Create(F.getContext(), "unwindbb", &F); + BasicBlock *UnwindBlock = + BasicBlock::Create(F.getContext(), "unwindbb", &F); Unwinds.push_back(new UnwindInst(F.getContext(), UnwindBlock)); Value *DispatchLoad = new LoadInst(CallSite, "invoke.num", true, DispatchBlock); SwitchInst *DispatchSwitch = - SwitchInst::Create(DispatchLoad, UnwindBlock, Invokes.size(), DispatchBlock); + SwitchInst::Create(DispatchLoad, UnwindBlock, Invokes.size(), + DispatchBlock); // Split the entry block to insert the conditional branch for the setjmp. BasicBlock *ContBlock = EntryBB->splitBasicBlock(EntryBB->getTerminator(), "eh.sjlj.setjmp.cont"); @@ -479,24 +486,21 @@ bool SjLjEHPass::insertSjLjEHSupport(Function &F) { for (unsigned i = 0, e = Invokes.size(); i != e; ++i) markInvokeCallSite(Invokes[i], i+1, CallSite, DispatchSwitch); - // The front end has likely added calls to _Unwind_Resume. We need - // to find those calls and mark the call_site as -1 immediately prior. - // resume is a noreturn function, so any block that has a call to it - // should end in an 'unreachable' instruction with the call immediately - // prior. That's how we'll search. - // ??? There's got to be a better way. this is fugly. - for (Function::iterator BB = F.begin(), E = F.end(); BB != E; ++BB) - if ((dyn_cast(BB->getTerminator()))) { - BasicBlock::iterator I = BB->getTerminator(); - // Check the previous instruction and see if it's a resume call - if (I == BB->begin()) continue; - if (CallInst *CI = dyn_cast(--I)) { - if (CI->getCalledFunction() == ResumeFn) { - Value *NegativeOne = Constant::getAllOnesValue(Int32Ty); - new StoreInst(NegativeOne, CallSite, true, I); // volatile - } + // Mark call instructions that aren't nounwind as no-action + // (call_site == -1). Skip the entry block, as prior to then, no function + // context has been created for this function and any unexpected exceptions + // thrown will go directly to the caller's context, which is what we want + // anyway, so no need to do anything here. + for (Function::iterator BB = F.begin(), E = F.end(); ++BB != E;) { + for (BasicBlock::iterator I = BB->begin(), end = BB->end(); I != end; ++I) + if (CallInst *CI = dyn_cast(I)) { + // Ignore calls to the EH builtins (eh.selector, eh.exception) + Constant *Callee = CI->getCalledFunction(); + if (Callee != SelectorFn && Callee != ExceptionFn + && !CI->doesNotThrow()) + insertCallSiteStore(CI, -1, CallSite); } - } + } // Replace all unwinds with a branch to the unwind handler. // ??? Should this ever happen with sjlj exceptions?